Corrugated metal roofing question

I am dismantling an old (wooden) pole barn and will be putting it back together on my property. The roof is 4/12 pitch with typical galvanized corrugated metal which is in great shape except the original nails were put in the "valley" instead of the crown/peak of the metal and as a result some of the 2x4's that run across the trusses will need to be replaced due to leaks over the years
To ensure I don't have leaks when I put the roofing back on I came up with two ideas....

Get good quality screws with rubber washers and use the exsisting holes in the tin...or put screws in peak and silicone the old nail holes.
I can't afford to go with all-new metal roofing.

What would you do?

Both. Use siilcone caulk and screws with rubber washers in the existing holes. And where it adds to the integrity add screws to the crown/peak.

I generaly find the metal siding is in bad shape near the ground, so use the roof on the walls and go for new roof tin?
Unfortuanalty this solution takes more money.
Depending on the corrugation pattern, maybe you can turn the material over making the valleys the ridges?

My updraggin was to put the screws/nails in the peaks--now-adays, I see all the roofers putting them in the valleys--of course I had to ask why & was asked if I ever tried to shovel snow off a roof w/ screws in the peaks?? Use the existing holes w/ roofing screws w/ washers--at least that seems to be the newer game plan---at least that's how I do it now--PLUS--it made sense even to me that silicone idea won't cause you anything but problems down the road

freetown fred wrote:... 8< ... that silicone idea won't cause you anything but problems down the road

More info --- why??

two things--1--it's a pain in the butt doing all those holes 2--no guarantee over time that the possibility of maybe even one small leak may present itself--I know the FORUM likes to go for the REAL technical, but, I'm going to stick with--if it ain't broke, don't fix it--when it comes to being up on the roof--I do it ONCE--I would put the silicone idea in my _____--riggin catagory--now that's just for filling the old holes--as far as useing it on the new screws/ old holes--get the bigger headed roofing screws/washers & it will be unnecessary--I think you can get 3/8 heads compared to the 1/4 inch heads--actually, I know you can get the bigger head screws

The woman two places up is having the contractors just this am finish up thier roof job. The 101 yrs old house went from a shingle roof to a metal one. They stripped the old, replaced - repaired wood and black papered. then they nailed down a furring strip layout for a small air space as well as a point for attachment of the metal.

They are fastining the metal with rubber washer hex headed screws. its green metal using green painted screws. 50 yr warrenty.

i think they are going on the peaks... ill take a few pics...

Yeah, I would go with roofing tar. What we used to call Creosote. It will outlast silicon. Theres gonna be alot of movement in that roof as it heats up and cools down. Both my workshop and my house has a Tin roof, and they have never leaked, as far as I can tell..

DVC500 at last wrote:Yeah, I would go with roofing tar. What we used to call Creosote. It will outlast silicon. Theres gonna be alot of movement in that roof as it heats up and cools down. Both my workshop and my house has a Tin roof, and they have never leaked, as far as I can tell..

When I was a teenager working on the farm, I'd get the job of painting the old metal roofs. I'd was given this asphalt based fiber infused aluminized paint to slather on the roof. Nice work for a hot day but cooler than the hay mound. Back then it was fibered with asbestos but I've seen similar stuff in HD. The old stuff lasted a long time.

Working in a steelmill most of my working life I`ve done lots of sheeting & roofing was always done with the screws on the peaks, siding in the valleys. Those roofers that do the valleys must want more work in their lifetime, & I sure wouldn`t be dumb enough to go up on a metal snow & ice covered roof to shovel. If you do slip on a galvanized roof with a good pitch about the only chance you have is the screw heads helping you stop. The newer galvalume roofing is put on with a clip system, the clips are attached first & the sheets snap in so nothing shows on top, that roof will most likely out live who ever has it installed.

Thanks for the replies.
I think I will get screws with a larger rubber washer like fred mentioned and put a dab of silicone on the hole then put the screw in like Yaunche suggested.
The R panel roofing (I think that's what it's called) always has screws in the flat bottom/valley but this older stuff always had the nails at or near the peak/crown from what I've seen in my lifetime. I think with the good quality screws that we have nowadays, in the valley should work.

rockwood wrote:I am dismantling an old (wooden) pole barn and will be putting it back together on my property. The roof is 4/12 pitch with typical galvanized corrugated metal which is in great shape except the original nails were put in the "valley" instead of the crown/peak of the metal and as a result some of the 2x4's that run across the trusses will need to be replaced due to leaks over the years
To ensure I don't have leaks when I put the roofing back on I came up with two ideas....

Get good quality screws with rubber washers and use the exsisting holes in the tin...or put screws in peak and silicone the old nail holes.
I can't afford to go with all-new metal roofing.

What would you do?

I have seen the recommendations change from valley to peak back to valley location again.

See link:

http://www.metalroofingwholesalers.com/installation.htm

Thanks for that link. I may do the "side lap sealant" too.

When ya gotta do it, ya gotta do it--that's why there's chimneys & ropes

samhill wrote:Working in a steelmill most of my working life I`ve done lots of sheeting & roofing was always done with the screws on the peaks, siding in the valleys. Those roofers that do the valleys must want more work in their lifetime, & I sure wouldn`t be dumb enough to go up on a metal snow & ice covered roof to shovel. If you do slip on a galvanized roof with a good pitch about the only chance you have is the screw heads helping you stop. The newer galvalume roofing is put on with a clip system, the clips are attached first & the sheets snap in so nothing shows on top, that roof will most likely out live who ever has it installed.

I don't care what anyone says, those rubber gaskets CRACK and LEAK. Use em but put shmootz on every one.